Official 33609 builder's tread. See 1st page for updates.

[wassx]

@igor:
thanks for asking! I'm still in the race. Little bit stressy at the moment.

-stef

 

[Amnezia]

[quote author="promixe"][quote author="Amnezia"]
Maybe i'm just stupid.. but what is "PLS"?... [/quote]

"PLS x'plain" in this case, I think, refers to "Please explain" =)

From your previous post:

Wich resistors are the "effect" one's... R23 and R41...?
In the BOM it's just R23 - 300 OHM / R41 - 1K2... ?

I personally only understood the word "BOM" =) So, all this means, you have to explain what you are trying to ask more clearly, because so far none of us can't understand what you mean, and therefore we are unable to help.

I think somehow you are confused that on the PCB silkscreen the outlines for those two resistors (R23 & R41) look somewhat bigger than the rest of the resistor outlines on the board. If this is your concern - those resistors should be no different in size or wattage, just make sure they are the right values (as it is printed right on the board and in the BOM)...[/quote]

Hi man.. thanks alot.. it was exactly what I was thinking.. I was looking at the PCB.. and some pictures of Igor's finished unit.. and it did not seem like "normal" metal resistors.. so I got confused.. Thanks for clearing that out.. :thumb:

The resistors for the elma's .. they are confusing me a little too.. in the BOM it seems that I should use other values.. but on the PCB there are other values again..
As long as I make sure only resistors with the values wrote on the PCB get attacked.. I'll be fine?..
(Looking away from the BOM some few times.. and just focus on the values on the PCB)... right?.. :?

 

[promixe]

in the BOM it seems that I should use other values..

Which version of BOM are you using? The only thing I've noticed is that the 120R resistor on LIM_THR (Elma board) is missing in EVERY BOM out there... So, make sure you order that one, otherwise you're gonna be missing a position =)
Also, R31 is 680R on the board, but in the schematic it's 560R... Those are the only things I've found with BOMs (I'm using 680R for R31, as is in everyone's BOMs)...

 

[maxheadroom]

i have a small question about the sifam knobs,
does anybody know the part number of these knobs?
thanks!!

 

[promixe]

[quote author="maxheadroom"]i have a small question about the sifam knobs,
does anybody know the part number of these knobs?
thanks!![/quote]

Depends on what look you're going after. =) JdJ and I went after the 21mm knobs (I liked the way his unit looked on page #17 of this thread and got the same knobs). The part # for these knobs is S210-250GRAY (which is 21mm light gray knobs with no pointer). And the caps are: C211BLUE/9 (21mm blue caps with white pointer).
However, if you're going after the look of the modern original 33609JD version - you will probably be better off getting 15mm knobs/caps (just use S15 and C15 in the part #s instead of S21/C21).

Word of warning: I had trouble fitting these 6mm collet knobs onto Lorlin switches - the switch shaft is too narrow and the collet slips on it even if you tighten it all the way to the max. I had to melt the shafts and hack the knob onto them in a non-pleasant time consuming way =) But you could never tell visually that there was such an obstacle. Anyone else can confirm this problem?

 

[Igor]

FLOATING ISSUES SOUNDCARD FLUKE ETC MEASURING EXPLAINED HERE

T3: Carnhill 9056 - people have reported it's working beautifully in the 33609...

OK

It took me some time to understand what is going on with your measures.

There is a thought in the back of my mind that I'm not measuring stuff correctly... =) Apply sine that reads 0.775VAC at T2 PRI+ (measured to T2 GND). Then measure voltages with my VAC meter everywhere in reference to T2/T1/T3 GND and convert to dBu with something like this - http://www.sengpielaudio.com/calculator-db-volt.htm. Since I don't have any special tools I have to do it the long way: measure AC voltage, convert to dBu, etc... Bypass IN, everything else OUT (unless trying to calibrate LIM or COMP)... So in other words, when I read out dB ratios, it's always + to GND or - to GND anywhere, not both...

First, your souncard probably balanced _and_ not floated
(dunno any soundcard with trafocoupled output

THEN

When you refer to soundcard output level,
measure with AC voltmeter beetween T2 pri+ and pri-,
only this is relevant....

because if measurement done on pri+ to gnd and there's 0.775v
and pri- to gnd (same 0.775V) it is actually 1.55V on primary of T2!!!!
I.e. you feed actually +6 db....

Then.

Same thing with pri of T1...
You need to refer to AC voltmeter's reading beetween
T2PRI+ and T2 PRI-.....

Then, when measuring on secondary of T1, it's - fortunately
connected to GND, all seems right....

And, if measurement was done T3+ to gnd, it was wrong...
because T3- was floated....

T3's wrong ratio:
Please measure T3SEC- to T3SEC+ with AC voltmeter,
should be 0db when between TP_D and gnd there's -8dB....

UPDATE: Just took T1 out of the board, measured +5.4dB with pri/sec in series... When feeding -31dBu sine into it standalone I read around -25.5dBu on secondary... So all is good with the traffo... What else would cause it to drop an additional 6dB within itself when in the circuit??

))

For good start,
Just ground sec- of T3, and feed 0.775V beetween T2 pri+/T2pri-....
Just.....remember, these freaky trunny's are floated.
It is actually two chokes coupled with magnetic field.
They don't know what is ground if no connection to ground...

For me it is easy to talk, 'cause I have an analyser with balanced in/out
(well, it is not allways balanced, there's button "float" on in/out).....
So, just please measure with AC voltmeter as above, and tell..
When measuring with scope output of T3, just connect sec- to gnd.
Good luck!


I have a feel everyhing is OK with this unit

Sorry again for my dead english

 

[promixe]

Hey guys! Quick and dirty update:

Igor: I KNEW I WAS DOING THIS WRONG =) Anyway... When I measured stuff like you suggested everything checked out perfect in terms of audio path ratios etc. However, when calibrating limiter/compressor sections I still couldn't match the parameters specified in the test procedures... More on that later, I can't think at the moment =)

Next: I didn't have enough patience, I calibrated the boards as close as I could, made sure they were even relatively to themselves. I brought the very original 33609, set it on top of my newly baked one =) Hooked it up and started listening (finally!) =)

So far I'm disappointed, but I believe this still might be incorrect calibration + some components responsible for release/attack times. Basically, my initial quick and dirty conclusion is my compressor is way too fast comparing to the original. Here are some audio files:

http://dev.ax-design.com/electronics/33609/33609-test1.mp3 - dry sample (yes, I know it's already compressed too much, not an ideal test material, blah blah =) But it's even more interesting and harsh scenario for the compressors to undergo.

http://dev.ax-design.com/electronics/33609/33609-test2.mp3 - My 33609. Low end is distorting a lot... Sounds like it's releasing too fast, attacking too fast as well (especially).

http://dev.ax-design.com/electronics/33609/33609-test3.mp3 - The original. Silky and smooth. Same signal, SAME LEVELS fed into it, SAME SETTINGS are dialed in. See pics for settings. I've used pretty unreal squashy setting for this test, but the original still behaves like the classic =)

I deliberatly left some empty space at the beginning of the processed files to capture the noise floor of each unit. They seem pretty similar loudness wise, with mine being slightly closer to full white spectrum, and the original having a little mid-rangy character to it.

Pics:

I think this will be pretty interesting, as noone so far has posted real audio examples / real comparisons with original 33609s here...

This is just the beginning =) I'm gonna fully test stuff tomorrow, I've got until monday afternoon to play with the original =)


Igor, thanks again for your clarifications man!

 

[Igor]

Release: please check 8k2/24k issue...
(there's some words on this tread)
cal procedure
etc
Maybe still some things in your unit swaped or wrong...
We compared clone built with Beclaire's/Marinair output
to original 33609, it was very close soundwise.
BTW, I rember, original was a bit out of calibration,
one channel had lower threshold (by 1-2 db or so),
anyway....still very close in sound.
I think, this is one of your first experiments
with complicated pro' stuff ladies.
Patience, care and attension is the best strategy
I had some previous experience with analog electronics from
medical stuff, like lasers and ultrasound.
Here, allmost all things written on paper..
Horowitz/Hill's patterns in different combinations.
Then, after building some tens (or more) of clones
of everything possible from 1072, 1176, mixbuzz, Sontec,
QE, to 1081, 33609, etc,
than some tens of protos of my own stuff including design
of whole mixing deck, I understood that pro audio is absolutely
freaky separeted field of electronics, different at all, sometimes
even fully absurd...but it has it's own "tao".
And a lot of thing are in "grey arrea"....
Lot of things are coming only from experience.
I allways happy to learn something new in "tao of audiotronics"...
Just continue with 33609 slowly, it is perfect way to learn.
Probably you'll find some points...
BTW, if there's guys who have fully calibrated working units
it will be interesting to compare sound samples of different trunnies, etc.

 

[keithcamilleri]

hi guys i am using carnhill iron for this project.

I am having a little trouble wiring the xformers, take vtb9046 for example do you connect pin 2 to primary negative ( short 3 and 4 ) and connect pin 5 to primary positive? is that the right way to go by?

http://www.audiomaintenance.com/downloads/carnhill_design_guide.pdf

thanks
keith

 

[promixe]

[quote author="keithcamilleri"]hi guys i am using carnhill iron for this project.

I am having a little trouble wiring the xformers, take vtb9046 for example do you connect pin 2 to primary negative ( short 3 and 4 ) and connect pin 5 to primary positive? is that the right way to go by?

http://www.audiomaintenance.com/downloads/carnhill_design_guide.pdf
[/quote]

One page back:

Primary: pin2 to PRI+, pin3 to pin4 (CT), pin5 to PRI-, pin6 to GND
Secondary: pin7 to SEC+, pin8 to pin9 (CT), pin10 to SEC-, pin11 unused

Also page #20 of this thread has info on this. If you wire pin2 to negative, make sure pin7 goes to negative secondary, just so you don't swap the phase. I wired pin2 to positive (pin 7 positive as well) because the drawing shows phase "dots" at those pins.

 

[Underthebigtree]

Hi guys -

I'm getting tantalizingly close with my unit, but hung up at the calibration procedure.

The unit is passing audio, but I'm having trouble with the metering during the diode bridge calibration (section 4). I can get the outputs adjusted properly by:
* assigning a 0dB 1kHz sin wave to the input,
* setting the CV voltage to 3 volts,
* setting the master bypass to the 'in' position
* attaching an alligator clip from the +CV in on the PS board to the link pin on the main board, right next to BC184
* tweaking RV2 to get -8dB at the output
* then readjusting R6 on PS board to get -20dB at output

No matter what, though, the meter becomes pinned as soon as I attach the alligator clip. I thought that the meter needed a 3K6 resistor (which it probably does, right?) which I added, but no change.

Any ideas?

Thanks,

Nick

 

[promixe]

Igor, pardon my ignorance, but how do you measure attack/release times/slopes with the scope? I looked through all the pictures on page 1 of this thread where you display scope shots with various attack/release conditions and I would like to verify my unit against them.

Do I send in a 0dBu 1k sine and measure at the output or elsewhere?

I guess the main and more general question is: how to measure (fairly precisely) compressor/limiter response and recovery times in milliseconds?

Thanks!



PS: Also, I'm getting a weird behavior when I switch the bypass OUT - the stereo image severely shifts (one channel louder than the other)... It wasn't that way when I was calibrating... hmm...

 

[promixe]

UPDATE: Ok! After more careful and systematic listening for attack/release issues I notice the following:

- Compressor sounds good except when switching to 100ms recovery. Then it starts sounding really grainy/distorted. Sounds like it might be R10 issue (i e 6K8 needs swapped for 24K). Has ANYONE noticed this behavior when using 6k8 resistor there or am I the only one? Has anyone used 24k there instead of the specified 6k8?

- R31 is 560R in the schematic but is labeled 680R on the board (see a couple of pages ago I mentioned it). This seems to be the resistor responsible for attack time. Correct me if I'm wrong though, but swapping it for 560R is going to make the attack FASTER?

- Limiter is where things start sounding really bad. The issue seems to be with the attack set to FAST. When it is at fast position everything sounds really distorted (horrible) especially in the low end. This seem to gradually disappear with increasing limiter recovery time. It is really pronounced and heavily distorted at 50 and 100ms settings, but starts to go away gradually at 200ms and up.

- with the attack switched to SLOW things sound somewhat grainy only at 50ms. The original 33609 I had over the weekend seemed to behave similarly in this scenario. When recovery switched to 100ms and up things sound smoother (normal).

I've checked R28 & R30 responsible for the attack selection on the limiter, they are both dead on 1k6 as specified. C14 is good too.

Clues/ideas? =)


UPD: Just swapped 6k8 for 24k on one of the channels - grainy stuff went away noticeably!!! Although I can still hear it it sounds more like the original 33609 in this aspect... Now I need to figure out the limiter section...

 

[wassx]

Ladies and Gentlemen!

My neve works.


:sam:

Just tested the two boards, and... oh yeah, I'm sitting here writing with a smile on my face.

My problem was, terrible as it can be, the cables to the frontpanels. Instead of the shield I splitted the cable to the two pins. A absolutly classical nonsense. (I think I passed point one on Igor's list. Put the right record on your turntable :wink: )

So I want to say "Thank you" to:
Chrisotop, who managed all the part ordering and helped me out with my problem
Igor, for this great project and help (I'm a noob, so you can guess how proud I am now)
To all people discussing their work in this forum, giving me a lot of hints

THANK YOU

I'm going back to work, some case work is missing and the knobs as well.

 

[promixe]

UPDATE: Ok, here is how the calibration goes:

5.2
When I calibrate RV5 to get -16dBu at the output with comp THD set to -20, then at THD set to 0 the output reads -1.2dBu...

When I calibrate RV5 to get -1dBu at the output with comp THD set to -2, then at THD set to 0 the output reads -0.2dBu... With the same RV5 position when I switch THD to -20, the output reads -14.14dBu... Would this be considered within normal behavior? Should I calibrate both boards like this? This seems to be the closest of both worlds (I mean a relatively okay balance between opposite THD settings)...

There is no way to accommodate every setting of the calibration to match the figures that are specified in the procedure...

4.2
Applying +16.3dBu to the input. RV4 calibrates fine for +4dBu output at +4 THD. However the output level starts gradually drifting as I increase THD and by the time it's at +13 the output is 0.5dB off (reads +12.5dBu). Would this be normal?

Also, when I switch attack from FAST to SLOW, the +4dBu output increases by +0.14dB - is this okay or should the level stay unaffected?


And then questions from my previous posts remain relevant:

- R31 is 560R in the schematic but is labeled 680R on the board (see a couple of pages ago I mentioned it). This seems to be the resistor responsible for attack time. Correct me if I'm wrong though, but swapping it for 560R is going to make the attack FASTER?

- Limiter is where things start sounding really bad. The issue seems to be with the attack set to FAST. When it is at fast position everything sounds really distorted (horrible) especially in the low end. This seem to gradually disappear with increasing limiter recovery time. It is really pronounced and heavily distorted at 50 and 100ms settings, but starts to go away gradually at 200ms and up.

- with the attack switched to SLOW things sound somewhat grainy only at 50ms. The original 33609 I had over the weekend seemed to behave similarly in this scenario. When recovery switched to 100ms and up things sound smoother (normal).

- how to measure (fairly precisely) compressor/limiter response and recovery times in milliseconds? How to make the slopes visual on the analog scope without any special equipment?


PS: swapped R10 from 6k8 to 24k - seems to have solved the issue of the compressor sounding grainy at 100ms recovery.

Igor, thanks for your help man! I think I'm very close to have solved all of the issues with my unit (half of which are probably my misunderstandings of electronics and not knowing tolerances of calibration ) =)[/code]

 

[Igor]

Guys, please, slow!!!!!
Overloaded with my stuff, can't think so quick

how do you measure attack/release times/slopes with the scope?

Hehe... a little trick.
My Boonton 1120 has a S/N measurement mode.
In this mode, it puts approx. 1 sec of sinewave at output than 2 sec of sielence. Putting threshold about 10 db of compression...
Hooking digital scope to CV and triggering some samples before.....
In other words, kinda tone burst method....
Possible to make tone burst signal with PC...
Just put 0.5 sec of sinewave at 0 output, the sielence, repeat....
With analog scope, it is a bit hard to trigger the attack.
Try to put second channel to input of compressor and trigger from second chan. With high brightness possible to see what happens.


There's some definitions of attack and release time...
Can be measured at 63% or 100% of gain reduction.
In LA-2 for example there's light effect memory of photocell,
than, manual shows 63%....anyway...
BTW, feedback compressor's timing can vary from amount of
gain reduction.

PS: Also, I'm getting a weird behavior when I switch the bypass OUT - the stereo image severely shifts (one channel louder than the other)... It wasn't that way when I was calibrating... hmm...

That's strange...please more info.

- R31 is 560R in the schematic but is labeled 680R on the board (see a couple of pages ago I mentioned it). This seems to be the resistor responsible for attack time. Correct me if I'm wrong though, but swapping it for 560R is going to make the attack FASTER?

There's some schemo versions...Mine shows 680R.
Actually, possible to put there 5k pot to change comp's attack time.

- Limiter is where things start sounding really bad. The issue seems to be with the attack set to FAST. When it is at fast position everything sounds really distorted (horrible) especially in the low end. This seem to gradually disappear with increasing limiter recovery time. It is really pronounced and heavily distorted at 50 and 100ms settings, but starts to go away gradually at 200ms and up.

- with the attack switched to SLOW things sound somewhat grainy only at 50ms. The original 33609 I had over the weekend seemed to behave similarly in this scenario. When recovery switched to 100ms and up things sound smoother (normal).

I've checked R28 & R30 responsible for the attack selection on the limiter, they are both dead on 1k6 as specified. C14 is good too.

Clues/ideas? =)

24k....
I copy-pasted everything from original old schemo.
And yes, 560r/680r, or 6k8/24k issues.

UPD: Just swapped 6k8 for 24k on one of the channels - grainy stuff went away noticeably!!! Although I can still hear it it sounds more like the original 33609 in this aspect... Now I need to figure out the limiter section...

:grin:

 

[Igor]

@underthebigtree:

The unit is passing audio, but I'm having trouble with the metering during the diode bridge calibration (section 4).
I can get the outputs adjusted properly by:
* assigning a 0dB 1kHz sin wave to the input,
* setting the CV voltage to 3 volts,
* setting the master bypass to the 'in' position
* attaching an alligator clip from the +CV in on the PS board to the link pin on the main board, right next to BC184
* tweaking RV2 to get -8dB at the output
* then readjusting R6 on PS board to get -20dB at output

No matter what, though, the meter becomes pinned as soon as I attach the alligator clip.
I thought that the meter needed a 3K6 resistor (which it probably does, right?) which I added, but no change.

Any ideas?

If unit is calibrated to unity gain with no makeup, CV=0,
then, applying CV=3V, it should attenuate audio by 8 db.
Maybe...check if meter is 1mA. There's 2 pots, one for adjustment of
VCA (RV2), one for adjusting meter (RV3)...
Turn down rv3, should work. No need for 3k6 resistor.

@ wassx

Ladies and Gentlemen!

(I think I passed point one on Igor's list. Put the right record on your turntable )

You see what happens!!!!! BTW, why, WHY Pat Metheny Secret Story
does not exists on vinyl?????? Ahhhhh....

My neve works.

All test proc is OK?
:guinness: :sam: :guinness: :sam:

:LAFROAIG:

:green:

UPDATE: Ok, here is how the calibration goes:

5.2
When I calibrate RV5 to get -16dBu at the output with comp THD set to -20, then at THD set to 0 the output reads -1.2dBu...

When I calibrate RV5 to get -1dBu at the output with comp THD set to -2, then at THD set to 0 the output reads -0.2dBu... With the same RV5 position when I switch THD to -20, the output reads -14.14dBu... Would this be considered within normal behavior? Should I calibrate both boards like this? This seems to be the closest of both worlds (I mean a relatively okay balance between opposite THD settings)...

Depending on ratio.
Yes, this can be sometimes freaky point. BC441's have different beta's
etc. I prefer to adjust threshold by putting it to 0 and feeding 0db when it just starts to compress, than same with -20.

There is no way to accommodate every setting of the calibration to match the figures that are specified in the procedure...

Just get as close as possible. If compressor seems to have too high ratio
put 441's with lower beta. and vise versa.

4.2
Applying +16.3dBu to the input. RV4 calibrates fine for +4dBu output at +4 THD. However the output level starts gradually drifting as I increase THD and by the time it's at +13 the output is 0.5dB off (reads +12.5dBu). Would this be normal?

Yes. See tolerances. In your case, adjust +4 for +3.7...this will compensate the drift.

Also, when I switch attack from FAST to SLOW, the +4dBu output increases by +0.14dB - is this okay or should the level stay unaffected?

Yes. You charging the cap' with less current (slower attack), so, nuff
unexpected.

And then questions from my previous posts remain relevant:

- R31 is 560R in the schematic but is labeled 680R on the board (see a couple of pages ago I mentioned it). This seems to be the resistor responsible for attack time. Correct me if I'm wrong though, but swapping it for 560R is going to make the attack FASTER?

Yap, answered

I think I'm very close to have solved all of the issues with my unit

Thank you, I think there'll be some people who will ask same questions and....using "search" will find the answers
Good luck!

 

[promixe]

BTW, why, WHY Pat Metheny Secret Story
does not exists on vinyl?????? Ahhhhh....

GEF24468 catalog number on german label Geffen... Limited edition 1992 LP =) It DOES exist =) Just VERY hard to find... I might know some people who have them here in the US =)

24k....
I copy-pasted everything from original old schemo.
And yes, 560r/680r, or 6k8/24k issues.

I didn't entirely get that... Those are the compressor section issues, I don't think they relate to the limiter section... I don't know what the next step should be to get rid of the limiter distortion/graininess...

 

[creativeblue]

Hey guys can someone please help me with my transformer problem...

I have here 2 x LO2567, 2 x LI 10468 and 2 x LI 10368
is it possible to

1.) use the 10368 instead of the 31267 for interstage

and

2.) use the LO2567 instead of the L1173 for output?

Does it make sense, I mean would you recommend this, or should I better buy the right ones?

AND, how to connect them all?

thanks

 

[Igor]

I didn't entirely get that... Those are the compressor section issues, I don't think they relate to the limiter section... I don't know what the next step should be to get rid of the limiter distortion/graininess...

No, I meant the difference beetween schematics, right one is
placed on AMS website.
Regarding the limiter, check everything on front pannel pcb, maybe there's an error on recovery related components....

Hey guys can someone please help me with my transformer problem...

I have here 2 x LO2567, 2 x LI 10468 and 2 x LI 10368
is it possible to

1.) use the 10368 instead of the 31267 for interstage

31267 used here as 2:1 line input trafo, not interstage.
10368 is 5k:2k4... Unpredictable.
Right trunny is 10468, it is most hard to get one...so,
I'd recommend to buy missing stuff from net.

2.) use the LO2567 instead of the L1173 for output?

With some riscue. 1173 used in +8 db connection.
2567 can be used in+4 db connection..
RV1 has only 2...3 db spare gain.
Right answer "no", but with the change of resistor's nominals on gain
make-up switch, possible.

Does it make sense, I mean would you recommend this, or should I better buy the right ones?

There was some stuff on this tread. Search.

AND, how to connect them all?

RTFM, or search.

(Neve trafo info at Dan Alexander's website for example)